Now more ample and exact data of mass and radius of neutron stars whose mass is close to \(1.4M_\odot \)  are available.
We collect the state-of-the-art data of the neutron neutron star in Fig. REF .
Horizontal bands around \(2 M_\odot \)  exhibit the data of large masses [1]}, [2]}, [3]}.
Gray zone represents the range obtained from the low mass X-ray binary (LMXB) data [4]},
error bars denote the analysis of a soft X-ray source observed in the NICER project [5]}, [6]},
and the red and the blue regions in the shape of wings correspond to the result of GW170817 (lower small wings) [7]}
and GW190425 (upper large wings) [8]}.
In the case of NICER two analyses were performed independently for a single object, so the two results are shown in the figure.
A red horizontal line is drawn at mass \(1.4M_\odot \)  for reference.
Observation data spread broadly on the mass-radius plane, but there is a narrow band in which all the data overalp.
For the mass \(1.4M_\odot \) , the commonly overlapping region restricts the radius in the range \(11.8-12.5\)  km.
